[Technical Field]
[0001] The present invention relates to a medical imaging device for obtaining image information
on multiple targets by simultaneously detecting fluorescence and Raman signals thereof,
and more particularly, to a medical imaging device including, for example, an endoscopic
device, an optical fiber probe, or long distance optical system employing an optical
fiber bundle probe for use in the in-vivo diagnosis of a disease of an animal including
a human.
[Background Art]
[0002] In modern medical science, in-vivo disease diagnosis is conducted using a variety
of imaging equipments such as MRI, PET, CT or endoscopy, each of which having different
scope of applications and advantages and disadvantages according to features thereof.
[0003] A medical imaging equipment proposed herein is similar to currently-available endoscope
in terms of the fact that the equipment is capable of acquiring two-dimensional image
of a specific site inside a human body or a site exposed to outside, using a probe
for insertion into the human body or a long distance optical system having a long-working
distance, while also providing real time-based qualitative analysis of multiple markers
using marker nanoparticles binding thereto and signals. However, the proposed imaging
equipment according to the present invention provides wider and more efficient range
of applications than endoscopes. The advantages are obtained from a technology that
simultaneously introduces multi signal components such as fluorescence and Raman signals
(to be specific, SERS signals) for marker nanoparticles, along with an optical system
which is capable of measuring the same with efficiency.
[0004] Endoscope non-invasively examines in-vivo the interior of organs such as digestive
system or respiratory system. Diagnosis method using the endoscope is photodynamic
diagnosis. Taking cancer diagnosis for example, invasive biopsy extracts biological
sample and culture cancer tissue. However, optical biopsy using endoscopy does not
require extraction of biologcal sample, but examines a suspected site by irradiating
light. This method thus saves pains on the patient' s side, and also offers convenience
and simple process on the side of a practitioner who can use images. Additionally,
endoscope offers advantages such as accurate cancer diagnosis and early detection
of cancer.
[0005] Conventional endoscopic examination involves observation on mucous membrane using
white light, using natural color representation of minute color shifting of mucous
membrane to provide detection of minimal disease change which is as small as several
millimeters. Meanwhile, the endoscopic investigation utilizing white light has insufficient
ability to recognize dysplasia generally occurring in Barrett esophagus or to detect
or diagnose colorectal polyp from non-tumor. Accordingly, biopsy and histopathologic
examination are separately required, to characterize positivity of a sample or malignancy.
However, biopsy has drawbacks mentioned above, and other shortcomings that it is prone
to sampling error, or increased cost and lengthening time of inspection due to need
for histopathologic examination.
[0006] Indeed, the white light-based endoscopic examination is considered to be a relatively
simple screen technology, and it is not considered to be as technological as implied
by the term endoscopic imaging' which generally refers to those technologies that
illuminate artificial lights in-vivo to living organism and construct an image based
on extraction/processing/interpretation of optical information that can be acquired
from the living organism.
[0007] To compensate for the above-mentioned drawbacks, fluorescent imaging technology was
proposed as the endoscopic imaging technology that utilizes fluorescence, according
to which presence or absence of a targeted material can be analyzed with increased
accuracy and in real time by distinguishing differences of colors or the like released
from normal and abnormal structures with a diagnostic equipment, using autofluorescence
which is naturally emitted from biological structure in response to a predetermined
frequency of laser light emitted thereto, or photosensitizer or biomarker selectively
remaining on a cancerous structure. The fluorescent imaging technology thus enabled
in-vivo analysis of presence of targeted material on living organism, with increased
accuracy and in a real-time basis (
US Pat. No. 7,285,089 et al.)
[0008] Fluorescence is used in a wide range of areas as a marker substance due to its high
sensitivity that can detect even a single molecule. A considerable number of imaging
technologies on marker materials have been proposed so far, including the in-vivo
fluorescence imaging technology on marker material as proposed by Gambir et al. However,
the fluorescence imaging technology has fundamental limitation particularly in terms
of simultaneous detection on multiple biomarkers due to relatively wider bandwidth
of the fluorescent spectra.
[0009] Accordingly, newer optical diagnostic technologies such as light scattering spectroscopy,
or optical coherence tomography have been suggested so far, and attempts were continuously
made to examine the states of the structures in details. The Raman spectrometry is
gaining attention, as its way of detecting vibration spectra of molecules gives availability
in a variety of optical fields and also it contains information about the structure
of molecules. Since the Raman spectrometry basically enables characterization of biological
constituents such as proteins or DNA based on the differences of molecular structures
thereof. The Raman spectrometry is thus considered to be effective in the detection
and diagnosis as to, for example, whether the polyp generated on mucous membrane is
tumor or nontumor.
[0010] Raman scattering based on vibration of molecules has optical characteristics which
are distinguished from the energy of incident light. Accordingly, Raman scattering
has narrow line width, and different scattering wavelengths depending on the types
and vibrations of the scattered molecules. Further, the Raman marker materials that
express Raman scattering do not show photobleaching characteristic like fluorescence.
By utilizing the above-mentioned optical characteristics, it will be possible to encode
a plurality of biomarkers distinctively within a narrow optical region, and it is
thus possible to detect signals from multiple biomarkers by single diagnosis performance
and to perform diagnosis on molecular structure-based sample using the Raman spectrometry.
[0011] Many studies are currently conducted on the imaging analysis equipment which utilizes
Raman spectrometry. By way of example,
JP Patent Publication No. 2002-136469 discloses an endoscopic apparatus employing a Raman spectrometer and an optical fiber,
and
JP Patent Publication No. 2009-511175 discloses an imaging apparatus which achieves microimages using a CARS signal. Further,
US2008/007716 discloses a Raman scattering light observation apparatus and endoscope apparatus.
[0012] However, many improvements are necessary to achieve accurate diagnosis by the Raman
spectrometry utilizing endoscopy, because the Raman signal emitted from the sample
itself is very weak, and most Raman signals are interfered with autofluorescence of
the sample, thus causing difficulty of discriminating Raman spectra of normal site
from those of abnormal site. That is, due to basically weak signal strength, the Raman
signals are not easily detected due to various noises or fluorescence.
[0013] US Pat. No. 2008-0007716 attempts to solve the problem of Raman signals being interfered with autofluorescence
of a sample, by providing a method for removing fluorescent interference with a Shifted
Excitation Raman Difference Spectroscopy (SERDS) system, but is not efficient enough
to overcome the basic characteristic of the Raman signals, i.e., weakness of the signals.
Further, most Raman spectrometry-based technologies suggested so far have not solved
inconvenience of having to record spectra by scanning with individual optical fibers
included in the optical fiber bundles and conduct imaging with respect to a specific
band. Therefore, notwithstanding the advantageously narrow line width of Raman signals,
practical utilization thereof for the simultaneous detection of multiple markers has
limits.
[Disclosure]
[Technical Problem]
[0014] The invention has been proposed to overcome the problems occurring in the prior art,
and an object of the present invention is to provide a method for simultaneously detecting
fluorescence and Raman signals for multiple targets of various diseases including
cancer of an incision of an animal including human in a procedure such as surgery,
and to a medical imaging device for simultaneously detecting multiple targets using
the method.
[Technical Solution]
[0015] The present invention has been proposed to overcome the problems mentioned above,
a method for simultaneously detecting fluorescence and Raman signals for multiple
targets in one embodiment may include steps of: injecting marker particles and one
or more marker particles including Raman marker particle and receptor into a body
of an animal including human; illuminating a laser light into the body of the animal;
and detecting, by separating an optical signal emitted after the illuminating into
a fluorescent signal and a Raman signal.
[0016] The above steps inject, and thus binds marker nanoparticles, which are surface-treated
to bind to targeting sites (target such as a disease or the like including specific
cancer cells), separating multi-signals emitted from the bound marker nanoparticles
and thereby determines location and type of the target.
[0017] The injecting may use various methods such as oral administration or injection by
needle, but not limited thereto. Additional steps may be included, such as, directly
spraying the marker particle onto a test structure inside the body of the animal using
a spraying means connected to a probe of the medical imaging device, or injecting
the marker particle through blood vessels.
[0018] Further, it may help to determine the relative location of the marker particle by
determining form and location of a test structure using Rayleigh scattering and autofluorescence
from cells and tissues, in addition to the fluorescence by the marker particle.
[0019] The detecting step may include steps of filtering, and thus removing laser light
from the emitted optical signal, dividing a path of the filtered optical signal into
a first and a second paths, and detecting a fluorescence signal from the optical signal
of the first divided path and detecting a Raman signal from the optical signal of
the second path, whereby the test structure can be imaged with the fluorescence signal
(i.e., autofluorescence naturally emitted from the sample itself) and analyzed with
the Raman signal.
[0020] The marker particle according to one embodiment of the present invention may additionally
include a fluorescence dye, in which case the location of the test structure can be
easily determined based on the fluorescence signal emitted from the fluorescence dye
and analyzed with the Raman signal. That is, if the fluorescence signal is naturally
emitted from the sample itself, two-dimensional imaging using general fluorescence
may be conducted, while if the fluorescence signal is originated from the fluorescence
dye included in the marker particle, this is used in the determination of the location
of the test structure. Further, after the detecting step, the step of analyzing the
test structure using the Raman signal is subsequently performed.
[0021] The marker particle for use in the medical imaging device and detecting method according
to the present invention may preferably use a surface-enhanced Raman marker particle
incorporating therein so-called illuminating component, which may include the Raman
reporter molecules adsorbed on metal nano particle including at least one of silver
(Ag), gold (Au) or copper (Cu), and fluorescence materials including dyes or quantum
dots co-added with core-shell structure nanoparticle including the same.
[0022] The probe particle may be so structured that the structure thereof may additionally
include silica shell surrounding the fluorescence dye, the Raman reporter molecules
and the metal nanoparticle or may be surface-treated to enhance other biocompatibility.
[0023] Further, the marker particle may include silica core particle to further increase
quality of SERS signal, in which the silica core particle may additionally include
magnetic nanoparticles to further expand the functionality of the marker particle.
[0024] That is, the present invention necessarily involves use of probe nanoparticles generating
strong Raman signal (particularly, SERS signals), which are attached to the targeted
site to investigate presence or absence of various targets and types of the targets
based on the characteristic Raman signal thereof, and preferably and additionally
generating fluorescence providing additional effects such as easy location tracing
of targets due to simultaneous emission of fluorescence signal and the Raman signal.
[0025] The most basic form of the marker particle has to emit enhanced Raman signal, which
may be provided in a core-shell form including a silica core incorporating therein
a metal nanoparticle including at least one of gold (Au), silver (Ag) or copper (Cu),
Raman marker material adhered onto the metal nano particle and a shell protecting
the same (Korean Pat. No.
10-073308, Korean Pat. No.
10-2008-011195). Another example can also be found in COIN (
Nano Letters., 2007, 7(2), 351-356) which discloses use of metal nano particle and bundle thereof as the core, and metal
and hollow shell.
[0026] In any case, using silica shell may protect the Raman marker material within nanoparticles,
increase biocompatibility of the nanoparticle, and facilitate introduction of receptors
for the binding to respective targets. The receptor may use a marker material-specific
receptor including any one selected from a group consisting of enzyme substrate, ligand,
amino acid, peptide, protein, nucleic acid, lipid, co-factor, carbohydrate or antibody.
[0027] Among implementations of the multi signals, a technology to use both fluorescence
and Raman signal is particularly advantageous for the imaging and multi detection.
A F-SERs Dot (Korean Pat. No.
10-2008-011195) as one embodiment of the present invention relates to additionally including fluorescence
dye to the shell in the process of forming the shell of the marker particle. In addition
to the above implementation, other examples are also possible. For example, the fluorescence
dye may be included in the core as a dye-doped silica, and the fluorescence dye itself
may be various fluorescence signal emitting material other than general organic dye,
such as quantum dot. As explained above, the fluorescence signal emitted from the
fluorescence dye may be advantageously used to determine the location of a test structure,
while the Raman signal is used to perform analysis on the same. In this process, fluorescence
signal may be naturally emitted from the test structure itself (i.e., autofluorescence),
and this may be used to perform two-dimensional imaging of the test structure with
the above-mentioned optical equipment. If the signal is originated from the fluorescence
dye included in the marker particle, this may advantageously used for determining
the location of the test structure.
[0028] To ensure that the simultaneous detection of multi signals is performed efficiently,
the fluorescence dye is so selected as to be placed in the longer wavelength domain
than the Raman signal to avoid overlapping with the Raman signal. The doubling of
the target number of the simultaneous detection is enabled because different targets
can be distinguished with the fluorescence signal before the discrimination by the
Raman signal. If (n) fluorescence dyes are introduced with respect to (m) Raman signal
marker particles, nano marker for simultaneously detecting (m x n) multiple targets
is possible. However, too many fluorescence markers are less preferred, considering
the wide bandwidth of fluorescence. Accordingly, if a plurality of fluorescence markers
are necessary, two to four fluorescence markers may be sufficient.
[0029] The present invention has been made to overcome the problems mentioned above, and
in one embodiment, provides a medical imaging device for simultaneously detecting
multiple fluorescence and Raman signal targets which may include a light source which
emits a laser light, an image guide which guides the laser light emitted from the
light source and optical signals of an incident light emitted from a test structure
or from marker particles which comprise a Raman marker material to emit Raman signals
and receptors and which are bound to the test structure, a light collector which is
connected to the image guide and which collects the optical signals, a scanner which
is connected to the image guide and which scans the optical signals of the incident
light, a light separator comprising a beam splitter connected to the scanner to separate
a path of the incident light into a first path and a second path so that the lights
are emitted separately, a fluorescence signal detector which detects fluorescence
signals from the optical signals of the first path separated at the light separator,
and a Raman signal detector which detects Raman scattering lights from the optical
signals of the second path separated at the light separator to construct a Raman spectrum.
[0030] The light collector may be implemented in various forms for broader use of the optical
equipment according to the present invention, and it is preferable to use optical
fiber bundle or remote distance optical system. Since the optical fiber bundle has
long length and small diameter, it is possible to directly contact this to the exposed
site of the incision in the process of surgery, or when implemented in the form of
slant tip, it is also possible to penetrate the same into skin for observation. Further,
the optical fiber bundle may be connected to the endoscope to allow easier observation
of a targeted site inside the living body. Further, while the end of the optical fiber
bundle can be exposed as is, it is possible to acquire minute confocal images in the
cell level, if microoptical system such as ball lens or GRIN lens, etc., is attached
and used. The long-working distance lens may be used as the remote distance optical
system, and this is particularly advantageous in observing the exposed target site
in a contactless manner.
[0031] The light separator may additionally include an edge filter which is placed between
the scanner, the fluorescence signal detector and the Raman signal detector, to removes,
by filtering, the laser light from the optical signals incoming from the scanner.
[0032] It is necessary that the light separator additionally includes the edge filter to
remove, by filtering, Rayleigh scattering light which corresponds to the wavelength
of the laser light which is relatively stronger among the optical signals incoming
from the scanner. It is also necessary to include a filter and a beam splitter to
separate the optical signals into Raman signals and fluorescence signals and guide
these to paths 1 and 2, to ensure that the fluorescence and Raman signals are collected
efficiently. The Rayleigh removal filter may be implemented with various specifications
and in various arrangements.
[0033] Further, the image guide and the light collector may additionally include a spray
means to spray the marker particles onto the test structure, in which the spray means
may additionally include a washing means to wash the test structure.
[Advantageous Effects]
[0034] According to the present invention, it is possible to easily perform simultaneous
detection of multiple targets using multiple optical signals emitted from a test structure.
[0035] Further, according to the present invention, since the Raman marker particles with
fluorescence components incorporated thereto are injected into a living body with
a spray device or the like, more accurate diagnostic results based on multiple biomarker
analysis can be obtained in a real-time basis.
[Brief description of drawings]
[0036]
Fig. 1 is a schematic view illustrating a structure and operation of a medical imaging
device for simultaneously detecting multiple fluorescence and Raman signal targets
according to the present invention;
Fig. 2 schematically illustrates a structure of a light collector of a medical imaging
device for simultaneously detecting multiple fluorescence and Raman signal targets
according to the present invention;
Fig. 3 is a schematic view of a constitution and an operation of a light separator
of a medical imaging device for simultaneously detecting multiple fluorescence and
Raman signal targets according to the present invention;
Fig. 4 is a graph schematically represents the spectrum of an optical signal generated
from the marker particles 300;
Fig. 5 is a view provided to briefly explain the process of separating and extracting
the fluorescence and Raman signals only, according to the present invention;
Fig. 6 illustrates an endoscopic probe implementing therein a spray means 70 according
to another embodiment of the present invention;
Fig. 7 illustrates the structure of F-SERS particles as an embodiment of the marker
particles 300 according to the present invention;
Fig. 8 shows SERS spectrum acquired using the signal detecting method and optical
fiber bundle according to the present invention;
Figs. 9 to 11 are fluorescence images taken by a medical imaging device for simultaneously
detecting multiple fluorescence and Raman signal targets according to an embodiment
of the present invention;
Fig. 12 provides photograph and graph representing real-time, simultaneous measure
of the fluorescence and spectrum shift;
Fig. 13 are graphs for comparing optical signal domains as collected in a medical
imaging device for simultaneously detecting multiple fluorescence and Raman signal
targets according to an embodiment of the present invention; and
Figs. 14 and 15 are graphs, showing when the natural Raman signals of the optical
fibers are removed according to establishment of the optical path.
[Best Mode]
[0037] The present invention will be explained in greater detail below with reference to
exemplary embodiments.
[0038] Fig. 1 is an overall, schematic view illustrating a structure and operation of a
medical imaging device for simultaneously detecting multiple fluorescence and Raman
signal targets according to the present invention.
[0039] Referring to Fig. 1, the medical imaging device according to the present invention
includes a light source 10, an image guide 21 including a bundle of optical fibers,
a light collector 20, a scanner 30, and a light separator 40, according to which accurate
diagnosis is performed as a path of the optical signal collected at the light collector
20 and passed through the optical fiber bundle 12 and the scanner 30 is divided into
a path 1 and a path 2, a location of a target material (T) (e.g., area the marker
particle is bound to targeting cell and tissue) is confirmed, and a type and a relative
amount of marked particle by the various Raman signals separated to path 2.
[0040] For an optical system that provides two dimensional imaging and mobility, a technically
well-developed and also well-known optical fiber bundle system 21 including scanner
30 is used, and marker nanoparticle (e.g., F-SERS dot, etc.), which uses both fluorescence
signal having technical superiority in terms of real-time imaging and Raman scattering
signal having superiority for multiple detection, is used, and fluorescence imaging
and Raman spectra are acquired for the signal detection by separating the fluorescence
signal and the Raman signal. Since the marker particle is bio-conjugated to recognize
biological molecule to diagnose, the targeted marker particle emits fluorescence and
Raman signals so that the optical signal delivered to the optical fiber bundle passes
through the optical system and separated into fluorescence imaging and Raman spectrum
for measure thereof. The measured fluorescence image indicates the targeted location
among the cells and tissues in a living organism, and the Raman spectrum indicates
the type of the targeted biological molecule. To be specific, since the Raman spectrum
has bandwidth below approximately 10 cm
-1, it is possible to use numerous different signals from the visible ray area, from
excitation energy and narrow spectrometry area below 2000 cm
-1, to fabricate various types of marker nanoparticles including Raman marker materials
that emit Raman signals at different locations, and also possible to simultaneously
detect multiple targeted biological molecules using such marker nanoparticles. The
Raman scattering signals used herein utilize the surface enhanced Raman scattering
(SERS) effect, and silver, gold and nano structures of various forms can be utilized
to acquire enhanced Raman scattering signals.
[0041] The optical signals of marker nanoparticles are constructed with fluorescence signals
which do not overlap with the SERS signals by the molecules adhered to silver and
gold surfaces. Since SERS signals can select various adsorbate molecules, numerous
different signals can be incorporated, and although the identical fluorescence signals
can be selected, relatively distinguishing signals may be incorporated within an optically
distinguishable range, in which case various types of signals can be implemented based
on combinations of SERS signals and fluorescence signals, and various immunoassay
strategies can be provided. By way of example, using the fluorescence signals emitted
from the fluorescence dye, it is possible to advantageously determine the location
of the test structure, and using the Raman signals, it is possible to analyze the
same. That is, if the fluorescence signal is naturally emitted from the sample itself,
two dimensional imaging using general fluorescence can be implemented, while if the
fluorescence signal is originated from the fluorescence dye included in the marker
particles, this can be used in the determination of a location of the test structure.
[0042] Fig. 2 schematically illustrates a structure of a light collector of a medical imaging
device for simultaneously detecting multiple fluorescence and Raman signal targets
according to the present invention. In one example, it is possible to use a lens system
(reference numeral '20a') such as so-called 'long-working distance lens', which is
used at a several centimeter working distance (e.g., intraoperative imaging equipment
(
FLARE: Fluorescence-assisted resection and exploration, Proc. SPIE, Vol. 6009, 60090C
(2005)) at a terminal end of the optical fiber bundle optical system 21, according to which
one is able to perform imaging and multi measure during a surgery; or use micro optics
such as GRIN lens 20d and Ball lens 20c, or use the optical fiber bundle as a probe
(i.e., without employing any lens at all) according to which one is able to perform
imaging and multi measure by measuring near-distance sample which is at a micrometer
working distance (
US 7,336,990 B2,
US 2009/0023999 A1)
[0043] The optical fiber bundle probe 20b, 20c, 20d may particularly be used in combination
with endoscope. The guide of the endoscope may additionally include a spraying means
which sprays the marker particles onto the test structure, to thus simultaneously
detect the fluorescence and Raman signals in real-time basis in vivo and thus provide
improved accuracy of the diagnosis. Meanwhile, additional functions of the medical
imaging diagnosis may be incorporated by combining the functions of the conventional
nuclear medical imaging equipment such as MRI or PET, in which case the nuclear medical
imaging equipment may detect the disease region, while the optical fiber bundle probe
may measure the corresponding region to construct multiple diagnostic image.
[0044] Fig. 3 is a schematic view provided to explain a path of an optical signal inside
a medical imaging device. The medical imaging device according to one embodiment may
include al light source 10, a light collector 20, an image guide 21, a scanner 30,
a light separator 40, a fluorescence signal detector 50, and a Raman signal detector
60. Further, the medical imaging device may additionally include a spray means 70
to spray marker particles onto a test structure in a living organism for the diagnostic
purpose.
[0045] First, the overall light path will be explained by referring to Fig. 3. The laser
light 1 generated from the light source 10 is reflected from an edge filter 42, passes
through a scanner 30, converged at a light emitting lens 22, transmitted to an optical
fiber bundle 21, and emitted from a terminal end of the light collector 20 connected
to the optical fiber bundle, that is, emitted preferably onto a test structure (T)
present in a living organism. An emitted light 2 that corresponds to the wavelength
of the laser light is filtered at the edge filter 42, and the filtered light is separated
at a beam splitter 41 so that 1/2(3) is delivered to the Raman signal detector 60,
while 1/2(4) is delivered to the fluorescence signal detector 50. The incident light
2 may be autofluorescence which is naturally emitted from the test structure (T) or
fluorescence that is generated from the marker particle 300 bound to the test structure
(T) in the prior injection step.
[0046] Note that it is the optical signal emitted from the marker particle 300 that is actually
used for the detection of abnormal site. That is, the autofluorescence is excluded,
considering a possible error due to existence of non-specific background signal that
may be included. However, the autofluorescence may be advantageously used for a conventional
two dimensional imaging.
[0047] The marker particle 300 may include Raman marker material which emits Raman signal
and a receptor, and may also preferably include a light emitting material including
fluorescence dye or quantum dot, BRET, or dye-doped silica including a complex of
fluorescence dye and silica. In a preferred embodiment of the present invention, SERS
particles utilizing surface enhanced Raman scattering effect (SERS effect) are used.
Accordingly, it is possible to detect both the fluorescence signal and the Raman signals
simultaneously.
[0048] To be specific, the fluorescence signal detected at the fluorescence signal detector
50 may be mainly divided into two types. One is autofluorescence which is naturally
emitted from the sample itself, and the other is fluorescence signal emitted from
a fluorescence dye included in the marker particle 300 according to the present invention.
According to the present invention, the marker particle 300 may or may not include
fluorescence dye. In the former's case, both the autofluorescence and fluorescence
signal from the fluorescence dye enter, while in the latter's case, only the autofluorescence
is included in the incident light. Further, in the former's case, the two dimensional
imaging is implemented by use of the autofluorescence at the fluorescence signal detector
50, while the location of the test structure (T) with the marker particle 30 attached
thereto is determined using the fluorescence signal originated from the fluorescence
dye. Further, since the latter's case uses the autofluorescence only, the fluorescence
signal detector 50 is able to perform two dimensional imaging process only. In the
former's case, that is, in the case where the fluorescence dye is included in the
marker particle 300, the signal from the autofluorescence is excluded from consideration
in the process of detecting abnormal structure. That is, the fluorescence signal,
which has relatively greater signal strength and is easier to detect, is used to determine
the location of the test structure (T), i.e., determine the location of the abnormal
site, while the Raman signal with narrow line width is used for the qualitative analysis
on the multiple targets.
[0049] Fig. 4 is a graph schematically represents the spectrum of an optical signal generated
from the marker particles 300 attached to the test structure T. Referring to Fig.
4, the fluorescence signal is emitted from the fluorescence dye, and is not autofluorescence.
That is, it is assumed that the marker particles 300 include fluorescence dye.
[0050] Referring to Fig. 4, the horizontal axis represents the shifting of the spectrum
in the form of spectral domain (cm
-1), and the vertical axis represents magnitude of the signal.
[0051] Referring to Fig. 4, the optical signal of the incident light 2 largely includes,
so-called Rayleigh scattering signal region ('laser line,
in the drawing), which is the direct reflective light of the laser light as emitted,
Raman signals, to be specific, 'SERS encoding region', and fluorescence signal region
('Fluorescence region' in the drawing), and each spectrum shifts to the respective
corresponding spectra domain and detected. That is, with reference to the laser light
(i.e., Rayleigh scattering), the Raman scattering shifts about 500 to 2000 cm
-1, and the fluorescence shifts about 2000 cm
-1 or above (when marker particles include fluorescence dye).
[0052] The Raman band shifts from the laser wavelength (from Rayleigh scattering region)
as much as the oscillation frequency of the molecule that causes Raman scattering,
and such shifting spans from several tens to several thousands cm
-1. Among these, the region below 900 cm
-1 is not used for the detection of the Raman band by the optical fibers. Accordingly,
the actually used regions among 900 to 2000 cm
-1 range may be approximately 520 to 560 nm, provided that the laser wavelength is 500
nm, for example. This particular region is used to encode the Raman signals, or to
be more specific, to encode the SERS signals, and the fluorescence signals use relatively
longer wavelength domain. The distinction among the wavelength domains may vary, depending
on the wavelength of the laser light.
[0053] In one embodiment of the present invention, the marker particles 300 are designed
by appropriately selecting the Raman signals as explained above, or the Raman signals
along with Raman marker particles and fluorescence dye to emit the fluorescence signal.
That is, using the marker particles 300, it is possible to obtain a spectrum that
has a sufficient difference to avoid interference of transitions of the Raman signal
region and the Fluorescence signal region with respect to the laser optical signal,
and it is thus possible to achieve the basic objective of the present invention, i.e.,
to separate and detect the Raman signals and fluorescence signals.
[0054] That is, since the Raman scattering does not interfere with the laser light or fluorescence,
the marker particles 300 and the medical imaging device according to the present invention
are capable of separating and detecting the Raman signals and the fluorescence signals
simultaneously.
[0055] To be specific, in one embodiment of the present invention, among the three types
of signals, the Rayleigh signals are removed by a predetermined optical filter, and
the rest signals, i.e., Raman signals and fluorescence signals are separately detected
so that the location of the targeted site is determined with the fluorescence signal
and the targeted site is analyzed with the Raman signal. To be more specific, the
fluorescence signal, which has stronger magnitude and is easier to detect, is used
for the determination of the location of the test structure, while characteristics
of the Raman spectrum are used for the multi in-vivo imaging in real-time basis, free
of interference among the signals emitted from the multiple targets, considering the
characteristics of the Raman spectrum are narrow line width, and variable shifting
depending on the type of molecules used as the Raman marker material and the wavelength
of the laser light. Furthermore, by implementing SERS particles as the marker particles
300, it is possible to provide the most efficient medical imaging device which compensates
for the shortcoming of the Raman spectrum, i.e., weak signal strength.
[0056] In other words, since the fluorescence is used to determine the location of the test
structure, while the Raman signals are used for the analysis purpose, it is not necessary
to scan the wide surface area to find the Raman signals and thus is possible to find
the location of the test structure in real-time basis. Further, since the Raman spectrum
of the entire targeted region is recorded, simultaneous signal detection for the multiple
targets is accomplished.
[0057] Further, the conventional medical imaging device constructs two dimensional image
using autofluorescence which is naturally emitted from the interior of a living organism,
and thus suffered shortcoming of less accurate diagnosis because of the non-specific
background signals included in the autofluorescence. The present invention solves
the above-mentioned problem of the conventional art, by exclusively using the fluorescence
signal emitted from the marker particles 300 and the Raman signals for the purpose
of detecting abnormal site.
[0058] It is particularly possible to provide confocal images for more accurate diagnosis,
because all of the laser light, autofluorescence naturally emitted from the sample
T, and Raman signals and fluorescence signals from the marker nanoparticles 300 are
passed through the same optical path.
[Mode for Invention]
[0059] Hereinbelow, the respective constitutions of a medical imaging device for simultaneously
detecting fluorescence and Raman signals for multiple targets according to the present
invention will be explained.
[0060] The light source 10 emits a laser light. The light source 10 may use a gas laser,
a solid state laser, or any of the known light emitting means without limitation.
In one embodiment of the present invention, the light emitted from the light source
10 may preferably range between 400 ∼ 800 nm, with resolution below 5 cm
-1, and be suitable for acquisition of Raman signals. The wavelength domain may be suitably
selected in consideration of the surface Plasmon resonance (SPR) with respect to precious
metals such as Ag, Au included in the SERS particles used as the marker particles
300 suitable according to the present invention, and therefore, various solid state
laser lights may be used at Ar ion laser lines of 488 and 514.5 nm, Kr-ion laser lines
of 531, 568 and 647 nm, and/or at the above-mentioned domains.
[0061] The image guide 21 and the light collector 20 include the optical fiber bundle 21,
and may include the light emitting lens 22, and various light collectors 20a-20d,
to guide a laser light 1 (i.e., outgoing light) from the light source, and an optical
signal 2 of an incident light emitted from the test structure, or from the marker
particles 300 which are attached to the test structure and include therein Raman marker
material to emit Raman signals and receptor, or additionally, fluorescence dye to
emit fluorescence signals. Using the image guide 21 and the light collector 20, the
laser emitted from the light source 10 can access the test structure T, and with the
use of remote distance optical system, it is possible to access the targeted location
with ease. If the optical fiber bundles are used as the optical collectors 20b, 20c,
20d, the heads at the terminal ends thereof may be directly manipulated or indirectly
operated when connected to the endoscope according to a driving device of the endoscope.
The image guide 21 and the optical fiber bundle light collectors 20b, 20c, 20d may
need to have suitable size for the purpose of clinical use, which may range several
mm in diameter.
[0062] The optical fiber bundles may include optical fiber bundles covered by protective
layers. To acquire high resolution images, sufficient optical fibers and minimum spaces
among the optical fiber cores are necessary. Generally, the optical fiber bundles
include several thousands to several hundred and thousand optical fibers which are
several µm in diameter, respectively. Both ends of the optical fiber bundles 21 may
be equipped with reflection-proofed glass plates to prevent reflection at both ends.
[0063] The light emitting lens 22 of the image guide 21 plays a role of converging laser
lights and emitting the same to the individual optical fibers inside the optical fiber
bundles, and to form a focal point that is closest as possible to the diffraction
limit, the emitting lens 22 is required to keep the aberration at the minimum and
also to keep from deteriorating the quality of wave front.
[0064] The scanner 30 is used to acquire confocal images by aligning paths of the outgoing
and incoming lights. Accordingly, any known system may be used as the scanner 30 without
limit, provided that the same forms confocal image. For example, an optical system
may be used, which includes a combination of one or more mirrors and aberration-free
lens to form confocal images. The examples may be found at various literatures including
US 7,447,539,
US 7,336,990 or
US 7,383,077.
[0065] The light separator 40 includes the beam splitter 41 which separates the path of
the incident light into a first path and a second path and emits the light accordingly,
and may additionally include the edge filter 42.
[0066] Referring to Fig. 3, the beam splitter 41 operates to divide the path of the light,
which includes the Raman signal component emitted from the marker particles 300, and
fluorescence signal component (autofluorescence and fluorescence originated from fluorescence
dye, respectively) emitted from the test structure T or the marker particles 300,
into the first and second paths 3, 4. By the separation of the light path, as explained
below, the fluorescence signals are detected from the fluorescence signal detector
50 using the optical signals separated into the first path 3, while the optical signals
separated to the second path 4 are used to detect the Raman signals at the Raman signal
detector 60 and construct the Raman spectrum. The beam splitter 41 may be implemented
as 50/50 separating cube or 50/50 separating plate.
[0067] The edge filter 42 operates to remove the laser light from the incoming light signals
2 from the scanner 30 by filtering. Because the Rayleigh light, which is the direct
reflection of the emitted laser light, does not give any meaning for the analysis
purpose of the test structure, these optical signals are filtered and removed. Accordingly,
the present invention may preferably employ the edge filter 42 to perform the filtering.
[0068] The edge filter 42 may preferably have approximately 5 nm of edge steepness (when
measured at optical density 6.0 wavelength and 50% transmittance wavelength) to ensure
that the Rayleigh scattering is removed effectively. If the edge filter 42 is included,
the light, from which the Rayleigh scattering is removed, leaving the Raman signals
and fluorescence signals, arrives at the beam splitter 41 and divided into the first
and second paths 3, 4.
[0069] The fluorescence signal detector 50 operates to detect the fluorescence signals from
the optical signals of the first path 4, from among the optical signals divided into
each path at the beam splitter 41. The fluorescence signal detector 50 may separately
include a rejection filter into the beam splitter to remove the Raman signals from
the optical signal of the first path 4 and thus to detect the fluorescence signals,
by removing optical components other than the fluorescence signals. Alternatively,
a band-pass filter may be included to selectively detect one or more fluorescence
signals. As explained above, depending on whether the fluorescence dye is included
in the marker particles 300 or not, the autofluorescence may only be detected, or
fluorescence originated from the fluorescence dye may additionally be detected.
[0070] The process of exclusively extracting fluorescence signals with the functions of
the edge filter 42 and the rejection filter or the band-pass filter in the medical
imaging device according to the present invention will be explained below.
[0071] Fig. 5 is a view provided to briefly explain the process of separating and extracting
the fluorescence and Raman signals only. Referring to Fig. 5, it is assumed that the
marker particles 300 include fluorescence dye.
[0072] Referring to Fig. 5, the optical signals emitted from the test structure include
Rayleigh scattering signals (in blue) which are the direct reflection of the initial
laser light from the same wavelength, Raman scattering signals (in green), and fluorescence
signals (in yellow, red). As the optical signals pass the edge filter 42, only the
Raman signals and the fluorescence signals remain, and therefore, the optical signals
are divided into the two light paths. After that, as the optical signals advancing
on the first path 4 are passed through the rejection filter or the band-pass filter,
the Raman signal component is removed, thus leaving the fluorescence signals only
which are detected at the fluorescence signal detector 50.
[0073] The fluorescence signal detector 50 may use, without limit, the known detector such
as an avalanche photodiode or PMT which can successively accommodate the signals.
[0074] The Raman signal detector 60 plays a role of constructing the Raman spectrum by detecting
the Raman scattering in the optical signals of the second path 3 which is split from
the optical signals at the beam splitter 41. The Raman signal detector 60 may include
a predetermined spectrometer and an optical diode array detector, or any other known
signal detector, provided that the employed detector is capable of detecting Raman
signals and constructing a spectrum based on the same and reading the signals. Accordingly,
the optical signals of the second path 3 is formed into spectrum at the spectrometer,
so that only the Raman signal region of the spectrum of the optical signal is read
at a CCD or a photodiode array detector.
[0075] In another embodiment of the present invention, a spray means 70 may be additionally
included, which sprays the marker particles 300 for the in-vivo diagnosis of the test
structure using the medical imaging device.
[0076] Referring to Fig. 6, in one embodiment, the spray means 70 may include a particle
storage tank 71a storing therein spray liquid A including the marker particles, a
particle conveying pipe 71b which conveys the spray liquid A from the particle storage
tank 71a to the test structure T, a washing liquid storage tank 72a storing therein
washing liquid B to wash the test structure to thus remove foreign substances other
than the marker nanoparticles, and a washing liquid conveying pipe 72b which conveys
the washing liquid B to the test structure T.
[0077] Accordingly, as a practitioner operates a driving device 200, or uses a spray gun
or the like, the liquid A for injection and the washing liquid B are sprayed from
the storage tanks 71a, 72a onto the test structure through the conveying pipes 71b,
72b.
[0078] That is, with the use of the spray means 71, it is not necessary to inject the marker
particles 300 into a body using needles or the like in advance, because it is possible
to spray the marker particles 300 included in the injection liquid A onto the test
structure in the process of conducting diagnosis with the endoscope. As a result,
more accurate spraying and reduced time for diagnostic procedure are achieved.
[0079] Further, it is possible to design the spray means 71 to also spray the washing liquid
B to provide clearer image of the test structure T by washing the same.
[0080] To be specific, the spray means 70 may be mounted to the heads (or probes) placed
on the leading ends of the image guide 21 and the light collector 20. The endoscopic
probe implementing therein the spray means 70 is illustrated in Fig. 6.
[0081] Referring to Fig. 6, the endoscopic probe may include the optical fiber bundles 20,
the particle conveying pipe 71b, the washing liquid conveying pipe 72b and other endoscopic
portions 11.
[0082] It is possible to use the probe of Fig. 6 to provide more accurate in-vivo diagnosis
in real-time basis, with the marker particles and washing liquid conveyed through
the particle conveying pipe 71b and the washing liquid conveying pipe 72b, in addition
to the optical fiber bundle 20 for collecting the emitted light of the test structure
T.
[0083] Next, the marker particles 300 according to the present invention will be explained.
Basically, the marker particles according to the present invention include Raman marker
material to emit Raman signals and receptors, and may additionally include fluorescence
dye. The fluorescence dye generate fluorescence signals, and the Raman marker material
generates Raman signals. Further, the receptors play a role of binding to the targeted
test structure T.
[0084] According to the present invention, the marker particles 300 holding therein the
receptors binding to specific suspected cancer cells are sprayed onto the structure
where the cancer cells are present, and the medical imaging device according to the
present invention determines location of the test structure based on the fluorescence
signals generated from the fluorescence dye included in the marker particles 300 and
also analyzes the presence or absence of the suspected cancer cells and properties
thereof at the test structure based on the determination as to whether the Raman signals
are detected or not. In an example where the fluorescence dye is not included, the
Raman signals, or to be more specific, the SERS signals are used for the direct detection
of the abnormal structure, while the autofluorescence is used for the imaging for
observation of the structure.
[0085] That is, if the receptors of the marker particles 300 are attached to specific cancer
cells, since the fluorescence signals included in the attached marker particles 300
(only autofluorescence naturally emitted from the cancer cells is detected when there
is not fluorescence dye included), and fluorescence signals generated from a specific
Raman marker material and Raman signal in the spectrum form are detected, it is possible
to determine as to whether or not the cancer cells are present. Further, considering
the very narrow line width of the Raman signal spectrum, when various receptors are
bound to several marker particles 300 and injected in vivo, interference with other
signals is not occurred. Therefore, it is possible to analyze Raman signals for a
plurality of marker particles 300 at once. That is, it is possible to detect and analyze
the signals for multiple targets.
[0086] According to the present invention, accurate diagnosis can be achieved, because the
fluorescence signals with relatively higher strength are used to easily determine
the location of the marker particles 300 attached to a specific site inside a body,
while the Raman signals are used to provide accurate spectrum analysis. The marker
particles 300 may be implemented in any available form such as granule, wire, or the
like, provided that the same include the fluorescence dye, the Raman marker material
and the receptors, and the above-mentioned basic elements may be combined with conventional
marker nanoparticles such as magnetic material, radioactive isotopes, quantum dots,
or photonic crystals.
[0087] The receptors may also be implemented as available ones, provided that the same specifically
attach to a specific test structure. An example of the receptors may include enzymatic
substrate, ligand, amino acid, peptide, protein, nucleic acid, lipid, co-factor, carbohydrate
or antibody, but not limited thereto. The test structure for attachment or reaction
or binding to the receptors for detection thereof, i.e., the target material may include
enzyme, protein, nucleic acid, oligosaccharide, peptide, amino acid, carbohydrate,
lipid, cells, cancer cells, cancer stem cells, antigen, aptamer, or other biologically-derived
molecules, and more preferably, proteins related to disease, but not limited thereto.
[0088] Despite the advantages of the marker particles 300 according to the present invention
explained above, the considerably weak signal strength of Raman signals still plays
as a daunting factor for the accurate diagnosis. Accordingly, an embodiment of the
present invention preferably uses SERS particles with enhanced Raman signal strength,
and more particularly, uses F-SERS particles as the marker particles 300 including
therein the fluorescence dye according to the present invention.
[0089] The SERS effect as used herein refers to rapid increase of Raman scattering by 10
3 to 10
14 folds when the molecules are adhered onto the surfaces of the metallic nanoparticles
such as gold, silver or copper. The SERS spectrometry based on such effect is thus
gaining increasing attention for possible development of high sensitivity technology
that can directly measure/analyze only one single molecule (i.e., monomer) in cooperation
with the nano technology which is fast developing.
[0090] The SERS particles that can provide the SERS effect may have the form in which the
Raman marker material and the receptors are added with metallic nanoparticles including
one or more of silver (Ag), gold (Au) or copper (Cu) to amplify the relatively weaker
Raman signals. The metallic nanoparticles may allow more incident laser beam to reach
the Raman marker material, and also plays a role of an antenna which amplifies the
emitted spectrum. To be specific, the SERS particles may be designed so that the Raman
marker material surround the surfaces of the metallic nanoparticles, or separate cores
(e.g., silica or ZnO cores) may be surrounded by metallic nanoparticles and Raman
marker materials. Furthermore, the above may be formed into aggregated structure or
to a wire-like structure.
[0091] For example, the SERS particles may be SOL-ID™ (Oxonica Materials Inc.) which has
a structure in which silver nanoparticles as the cores are surrounded by Raman marker
material and silica shells in sequence, or COINS (
Composite Organic-Inorganic Nanoparticles) (NANO LETTERS, 2005, Vol.5, No.1, pp49-54) including aggregates of condensed gold and silver nanoparticles in the presence
of Raman organic marker material as suggested by Xing Su et al., but not limited thereto.
Additionally, the SERS particles may use the particles of Korean Pat. No.
892629, or Korean Patent Publication No.
2010-4458, or material made by binding thiol group and Raman marker material to terminus of
DNA 3' and incorporating ligand to perceive specific biological substance to 5' terminus,
or carbon nanotubes (
KEREN et al., PNAS 2008; 105; 5844) or various other SERS particles or materials emitting strong Raman signals, but
not limited thereto.
[0092] In one embodiment of the present invention, in addition to maximize the Raman signals
using the SERS particles, it is also possible to use the F-SERS particles to which
the fluorescence dye is included, to thus enable simultaneous detection of both fluorescence
signals and Raman signals.
[0093] Fig. 7 illustrates the structure of F-SERS particles as one embodiment of the marker
particles 300 according to the present invention.
[0094] Referring to Fig. 7, in one embodiment of the present invention, the F-SERS particles
have a basic structure that includes core particles 1 at the core, marker shells which
surround the core particles 1 and which include metallic nanoparticles 2, Raman marker
material 3 and fluorescence dye 4, and one or more antibodies 6 attached to the marker
shells as one type of receptor. In addition, silica shells 5 may additionally be included,
surrounding the core particles 1, the metallic nanoparticles 2, the Rana marker material
3 and the fluorescence dye 4, in which case the antibodies 6 are attached to the outer
surfaces of the silica shells 5 (see Fig. 7).
[0095] The core particles 1 may include at least one of silica, silica including therein
dispersed dye or silica including therein small cores of magnetic material (or radioactive
isotope), metallic nanoparticles or a bundle of the same. The magnetic material may
use metal or metal oxide such as CO, Mn, Fe, Ni, Gd or MM'
2O
4 and M
xO
y (where, M and M' are Co, Fe, Ni, Mn, Zn, Gd, Cr, 0<x≤3, 0<y≤5) individually or in
combination. The F-SERS particles according to the present invention preferably use
silica as the core particles 1.
[0096] The metal of the metal nanoparticles may use at least one of silver (Ag), gold (Au)
and copper (Cu) that generates so-called SERS effect.
[0097] Any material including molecules to generate Raman signals may be used as the Raman
marker material 3, which may be selected from a group consisting of 2-methyl benzenethiol,
4-methyl benzenethiol, 4-mercaptopyridine, 2-naphthalenethiol, 4-methoxy benzenethiol,
3-methoxy benzenethiol, 3,4-dimethylbenzenethiol, thiophenol and 3,5-methoxy dimethylbenzenethiol),
or any other material that has unique SERS spectrum with high binding force with the
metallic nanoparticles 2.
[0098] Organic or inorganic fluorescence dye may be used as the fluorescence dye 4, and
in one example, the known organic marker material such as fluorescent rhodamine, radioactive
isotope or light emitting semiconductor quantum dot such as Zn-S capped CdSe may be
used. The silica shells 5 have high biocompatibility since these are harmless to human
or animal body, and surface modification is easy. Therefore, the silica shells 5 can
be used as the final shells.
[0099] The antibodies 6 have specific terminus to bind to specific molecule or cell. In
one embodiment of the present invention, various antibodies 6 or other receptors may
be implemented altogether, to thus induce a plurality of SERS particles, to which
the receptors are applied, to emit multisignals.
[0100] In one preferred embodiment, in selecting respective constituents of F-SERS particles
as the marker particles 300, those fluorescence materials and Raman marker materials
may be appropriately selected so that the fluorescence signals generated from the
fluorescence dye 4 are placed at longer wavelength domain than the SERS signals generated
from the Raman marker material 3, to thus avoid interference of the two signals.
[0101] The method for fabricating the SERS particles and specific characteristics thereof
can be found in Korean Patent Publication No.
2007-14964 filed by the inventors of the present invention. However, F-SERS particles are only
one of examples, and other modified examples may also be implemented. For example,
fluorescence particles may be incorporated into various configurations of the SERS
particles explained above.
[0102] The medical imaging device for simultaneously detecting multiple fluorescence and
Raman signal targets according to embodiments of the present invention has been explained
above. Although the medical imaging device according to the present invention may
be representatively implemented as a structure included in the endoscope to investigate
test structure by being introduced into a living body, other embodiments are possible.
Accordingly, the medical imaging device according to the present invention may be
applied for various embodiments of imaging systems in addition to endoscope. For example,
the medical imaging device according to the present invention may be implemented as
a probe to accurately examine test structure of the incision in the process of surgery,
or other forms of probes.
[0103] The present invention proposes a method for simultaneously detecting fluorescence
and Raman signals for multiple targets using the medical imaging device and F-SERS
particles explained above. The method for simultaneously detecting fluorescence and
Raman signals of multiple targets according to one embodiment of the present invention
may include steps of injection (S10), emitting light (S20), scanning (S30) and detecting
(S40).
[0104] At injection step (S10), at least one marker particle 300 to which a plurality of
various receptors are preferably attached, are injected into a body of an animal including
human, in which the marker particles 300 may be injected by oral route, or by needle,
or by a general injection method, or using the spray means 70 connected to the endoscopic
probe as explained above.
[0105] The injection step (S20) involves emitting a laser beam into the body of the animal,
in which the laser beam generated from the light source 10 is emitted to the test
structure via the optical fiber bundle 21 and the optical collector 20.
[0106] At scanning step (S30), the marker particles 300 and the laser beam emitted from
the test structure of the interior of the body of the animal are scanned. This step
may preferably be performed by forming confocal images using the scanner 30.
[0107] That is, the light emitting step (S20) and the scanning step (S30) may be performed
simultaneously. For example, using the optical fiber bundle, the laser may be emitted
to the individual optical fibers within the bundle, while being scanned at the same
time.
[0108] The detecting step (S40) involves separately detecting the emitted optical signals
into fluorescence signals and the Raman signals, and may include, in particular, the
steps of removing laser reflective light (S41), separating optical paths (S42) and
separately detecting (S43).
[0109] The laser reflective light removing step (S41) includes removing, by filtering, optical
component (i.e., Rayleigh light) corresponding to the laser beam from the scanned
optical signals, using the edge filter 42.
[0110] The light path separating step (S42) includes separating the path of the filtered
optical signals into a first path 3 and a second path 4.
[0111] The separately detecting step (S43) includes the steps of detecting fluorescence
signals from the optical signals of the separated first path 3, and detecting Raman
signals from the optical signals of the separated second path 4. The principles of
operation are referred to the explanation provided above with reference to the medical
imaging device according to the present invention.
[0112] With the method for simultaneously detecting fluorescence and Raman signals for multiple
targets according to various embodiments of the present invention, real-time detection
of multiple targets is possible. Particularly, because of a method for separately
detecting fluorescence and Raman signals using separate marker particles, the embodiments
of the present invention provides greatly improved advantages such as absence of non-specific
background signals such as autofluorescence. Therefore, it is possible to utilize
the characteristics explained above for the purpose of in vivo and in situ diagnoses
using endoscopy, or image guided surgery, or the like.
[0113] Fig. 8 is a SERS spectrum acquired using the signal detection method and optical
fiber bundle according to the present invention.
[0114] Referring to the SERS spectrum of Fig. 8 measured with the optical fibers, the Raman
signals naturally generated from the optical fibers are observed in the region below
900cm
-1. Accordingly, it is possible to use optical signals from the range between 900cm
-1 and 2000cm
-1 for SERS encoding.
[0115] Figs. 9 to 14 show results of experiments conducted with the medical imaging device
for simultaneous detection of multiple targets, based on the method for simultaneously
detecting fluorescence and Raman signals for multiple fluorescence and Raman signal
targets and medical imaging device for simultaneously detecting multiple targets using
the method, according to the embodiments of the present invention.
[0116] As a result of experimenting with the medical imaging device prepared according to
the present invention to simultaneously detect the multiple fluorescence and Raman
signal targets, the technology of acquiring spectrum while maintaining fluorescence
imaging function, enabled successful separation of paths for incident light and measure
light with the use of optical fiber optical system, without having to change the optical
path of the laser scanning unit, and by incorporating a combination of fluorescence
imaging technology and Raman spectrometry function, the fluorescence and spectrum
were measured simultaneously.
[0117] Further, Figs. 9 to 11 are fluorescence images taken by a medical imaging device
for simultaneously detecting multiple fluorescence and Raman signal targets according
to an embodiment of the present invention, which confirm the fact that images with
high resolution are acquired.
[0118] Further, Fig. 12 provides photograph and graph representing real-time, simultaneous
measure of the fluorescence and spectrum shift which confirm the fact that the present
invention can measure the fluorescence images and the spectrum at the same time and
in real-time basis.
[0119] Fig. 13 are graphs for comparing optical signal domains as collected in a medical
imaging device for simultaneously detecting multiple fluorescence and Raman signal
targets according to an embodiment of the present invention. Since the optical signals
have scattering light from the laser beam itself, Raman signals naturally emitted
from the optical fibers, Raman signals generated from the marker particles, and fluorescence
signals are overlapped with one another, it was confirmed that by establishing an
optical path, it was possible to achieve the technology to separate/collect the natural
signals from the optical fiber, the Raman signals of the marker particles and the
fluorescence signals.
[0120] Figs. 14 and 15 are graphs, showing when the natural Raman signals of the optical
fibers are removed according to establishment of the optical path. These confirm the
fact that by establishing an optical path, it was possible to achieve the technology
to separate/collect the natural signals from the optical fiber, the Raman signals
of the marker particles and the fluorescence signals.
[0121] The foregoing embodiments and advantages are merely exemplary and are not to be construed
as limiting the present invention. The present teaching can be readily applied to
other types of apparatuses. Also, the description of the exemplary embodiments of
the present inventive concept is intended to be illustrative, and not to limit the
scope of the claims, and many alternatives, modifications, and variations will be
apparent to those skilled in the art.
[Industrial applicability]
[0122] The present invention is industrially applicable, since it relates to a medical imaging
device including an endoscope employing therein optical fiber bundle probe for use
in the in-vivo disease diagnosis of an animal including a human, an optical fiber
probe, or a remote distance optical system.